1. Field of the Invention
The present invention relates to a method of monitoring a life-or-death state of a host computer connected to a network intended to confirm a life-or-death state of a plurality of host computers connected to the network, a life-and-death monitoring system and a computer program suitable for the system and, more particularly, to the monitoring of a life-or-death state of a host computer to be managed which is realized by sequential transfer of a life-and-death monitoring packet.
2. Description of the Related Art
There is a conventional method of conducting communication with a plurality of host computers connected to a communication network. In such a case of communication with a plurality of host computers connected, it is necessary to check whether each host computer is communicable, that is, it is dead or alive.
In the following, description will be made of a life-and-death monitoring method at a conventional life-and-death monitoring system with a plurality of host computers connected to a network.
As shown in FIG. 5, for example, in a case of transmission with a management host computer A and to-be-managed host computers B, C and D connected through a network 100, the management host computer A for managing these host computers B, C and D to be managed sends a life-and-death monitoring packet to all of the host computers B, C and D to be managed and receives a response returned from the life-and-death monitoring packet, thereby realizing transmission.
In such a case where the number of host computers to be managed is small as mentioned above, transmission and response between the management host computer A and the host computers B, C and D to be managed is conducted smoothly. However, in a case where the number of host computers to be managed is large, for example, where a number N of host computers to be managed are provided, life-or-death state monitoring results in having a maximum number N of life-and-death monitoring packets at a time on the network. Existence of such a large number of life-and-death monitoring packets contributes to an increase in the load on the network and hinders communication.
At the same time, the management host computer needs to transmit a life-and-death monitoring packet to each of the number N of host computers to check its life-or-death state, which results in an increase in the load on the management host computer itself.